The present invention relates to signal processing in a receiver system, and more particularly, to a shared processor architecture applied to functional stages configured in a receiver system for processing signals from different transmitter systems (e.g., GNSS systems) and method thereof.
Please refer to FIG. 1. FIG. 1 is a block diagram illustrating a first conventional global navigation satellite system (GNSS) receiver 10. The GNSS receiver 10 comprises an antenna 12, an RF front end 14, an analog-to-digital converter (ADC) 16, a plurality of functional stages 18a, 18b, 18c performing correlation processing, acquisition/tracking processing and positioning/navigation processing respectively, and a time base generator 19. The GNSS receiver 10 supports a single GNSS system (e.g., GPS, Galileo, or GLONASS). The antenna 12 is used for receiving an RF signal transmitted from a satellite of the supported GNSS system, and the RF front end 14 converts the RF signal into an intermediate frequency (IF) signal. Next, the analog-to-digital converter (ADC) 16 converts the incoming analog IF signal into a digital IF signal which is further fed into the following functional stage 18a. As shown in FIG. 1, the correlation processing, acquisition/tracking processing and positioning/navigation processing are executed in order to complete the positioning signal processing. Furthermore, the time base generator 19 is coupled between the functional stages 18a and 18b, and is managed by the functional stage 18b and configured to provide the time base to the functional stage 18a for informing the functional stage 18a of the integration period of correlating the input signal with a local code replica. Since the details of the GNSS receiver 10 are known to those skilled in this art, further description is omitted for brevity.
To offer better positioning precision, a GNSS receiver supporting multiple GNSS systems is provided. Referring to FIG. 2, it is a diagram illustrating a second conventional global navigation satellite system (GNSS) receiver 30. The GNSS receiver 30 comprises an antenna 32, an RF front end 34, an ADC 36, a plurality of functional stages 38a, 39a, 40a performing correlation processing, a plurality of functional stages 38b, 39b, 40b performing acquisition/tracking processing, a plurality of functional stages 38c, 39c, 40c performing positioning/navigation processing, and a plurality of time base generators 42a, 42b, 42c. The GNSS receiver 30 is designed to support multiple GNSS systems, such as GPS, Galileo, and GLONASS, based upon the architecture shown in FIG. 1. The components of the same name in FIG. 1 and FIG. 2 have identical operation and functionality, and further description is omitted for brevity. In the GNSS receiver 30, a combination of the functional stages 38a, 38b, 38c is implemented for processing signals from the first GNSS system (e.g., GPS), a combination of the functional stages 39a, 39b, 39c is implemented for processing signals from the second GNSS system (e.g., Galileo), and a combination of the functional stages 40a, 40b, 40c is implemented for processing signals from the third GNSS system (e.g., GLONASS).
As shown in FIG. 2, the GNSS receiver 30 is designed to allocate a signal processing chain, which contains a plurality of functional stages, to each of the supported GNSS systems. However, the signal processing chains are not active at the same time. For example, in a case where the signal processing chain including the functional stages 38a, 38b, 38c is enabled to process signals from a GPS satellite, the remaining signal processing chains are idle. As a result, the architecture of the GNSS receiver 30 supporting multiple GNSS systems is not cost-efficient and resource-efficient. As a result, a novel GNSS receiver architecture supporting multiple GNSS systems is needed.